U.S. patent application number 11/212097 was filed with the patent office on 2006-03-09 for microlens array sheet having black matrix and method of manufacturing the same.
This patent application is currently assigned to LG Electronics Inc.. Invention is credited to Hyouk Kwon, Gun-Woo Lee, Tae-Sun Lim, Chang-Hoon Oh, Ki-Won Park, Dong-Mug Seong, Young-Joo Yee.
Application Number | 20060050397 11/212097 |
Document ID | / |
Family ID | 36111820 |
Filed Date | 2006-03-09 |
United States Patent
Application |
20060050397 |
Kind Code |
A1 |
Oh; Chang-Hoon ; et
al. |
March 9, 2006 |
Microlens array sheet having black matrix and method of
manufacturing the same
Abstract
Disclosed herein are a microlens array sheet having a black
matrix and a method for manufacturing the same. The manufacturing
method includes a) the step of defining the regions of light
apertures, through which condensed light passes, in a negative-type
light-sensitive resin layer by radiating and condensing parallel
light after sequentially laying a microlens array layer, a
transparent support substrate or film layer and the negative-type
light-sensitive resin layer one on top of another, and b)
eliminating portions other than the regions of the light apertures
formed in the light-sensitive resin layer, and forming a black
matrix layer in regions where the portions have been
eliminated.
Inventors: |
Oh; Chang-Hoon; (Seoul,
KR) ; Kwon; Hyouk; (Seoul, KR) ; Lim;
Tae-Sun; (Suwon-si, KR) ; Yee; Young-Joo;
(Seongnam-si, KR) ; Park; Ki-Won; (Anyang-si,
KR) ; Seong; Dong-Mug; (Ansan-si, KR) ; Lee;
Gun-Woo; (Dalsco-gu, KR) |
Correspondence
Address: |
MCKENNA LONG & ALDRIDGE LLP
1900 K STREET, NW
WASHINGTON
DC
20006
US
|
Assignee: |
LG Electronics Inc.
Seoul
KR
LG Micron Ltd.
Gumi-si
KR
|
Family ID: |
36111820 |
Appl. No.: |
11/212097 |
Filed: |
August 26, 2005 |
Current U.S.
Class: |
359/619 |
Current CPC
Class: |
G02F 1/133512 20130101;
G02F 1/133526 20130101; G03B 21/602 20130101; G03F 7/0007
20130101 |
Class at
Publication: |
359/619 |
International
Class: |
G02B 27/10 20060101
G02B027/10 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 28, 2004 |
KR |
10-2004-0068245 |
Claims
1. A method of manufacturing a microlens array sheet having a black
matrix layer, comprising the steps of: defining regions of light
apertures, through which condensed light passes, in a negative-type
light-sensitive resin layer by radiating and condensing parallel
light after sequentially laying a microlens array layer, a
transparent support substrate or film layer, and the negative-type
light-sensitive resin layer one on top of another; and eliminating
portions other than the regions of the light apertures defined in
the light-sensitive resin layer, and forming a black matrix layer
in regions where the portions have been eliminated.
2. The method as set forth in claim 1, further comprising the step
of forming a light diffusion layer on a bottom surface of the black
matrix layer.
3. The method as set forth in claim 2, wherein the light diffusion
layer is a lenticular or holographic surface-type light diffusion
layer.
4. The method as set forth in claim 1, wherein the regions of light
apertures, through which the condensed light passes, defined in the
negative-type light-sensitive resin layer are formed such that an
area of each region through which the condensed light enters is
smaller than an area of the region through which the condensed
light is emitted.
5. The method as set forth in claim 1, wherein the light-sensitive
resin layer has a light transmittance of more than 90%.
6. The method as set forth in claim 1, further comprising the step
of eliminating portions of the light-sensitive resin layer formed
in the regions of the light apertures.
7. The method as set forth in claim 6, further comprising the step
of forming a light diffusion layer on a bottom surface of the black
matrix layer.
8. The method as set forth in claim 7, wherein the light diffusion
layer is a lenticular or holographic surface-type light diffusion
layer.
9. The method as set forth in claim 7, wherein the regions of light
apertures, through which the condensed light passes, defined in the
negative-type light-sensitive resin layer are formed such that an
area of each region through which the condensed light enters is
smaller than an area of the region through which the condensed
light is emitted.
10. The method as set forth in claim 7, wherein the light-sensitive
resin layer has a light transmittance of more than 90%.
11. A microlens array sheet having a black matrix layer, comprising
a microlens array layer, a transparent support substrate or film
layer, and the black matrix layer in which regions of light
apertures are formed such that an area of each region through which
the condensed light enters is smaller than an area of the region
through which the condensed light is emitted, the microlens array
layer, the transparent support substrate or film layer, and the
black matrix layer being laid one on top of another.
12. The microlens array sheet as set forth in claim 11, further
comprising a light diffusion layer on a bottom surface of the black
matrix layer.
13. The microlens array sheet as set forth in claim 12, wherein the
light diffusion layer is a lenticular or holographic surface-type
light diffusion layer.
14. The microlens array sheet as set forth in claim 11, wherein the
regions of light apertures are filled with a light-sensitive
layer.
15. The microlens array sheet as set forth in claim 14, further
comprising a light diffusion layer on a bottom surface of the black
matrix layer.
16. The microlens array sheet as set forth in claim 15, wherein the
light diffusion layer is a lenticular or holographic surface-type
light diffusion layer.
Description
[0001] This application claims the benefit of Korean Patent
Application No. 2004-40068245, filed Aug. 28, 2004, which is hereby
incorporated by reference for all purposes as if fully set forth
herein.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates generally to an optical sheet
that is applicable to the screen of a display system and, more
particularly, to a microlens array sheet having a black matrix and
a method of manufacturing the same, in which, in order to form the
black matrix that is a light blocking layer that covers regions
other than light apertures, a light aperture pattern is formed
through an exposure process performed toward a microlens sheet and
on a light-sensitive resin layer under the microlens sheet, and the
regions other than the light apertures are filled with a black
pigment having a considerably low light reflective index and a
considerably low transmittance.
[0004] 2. Description of the Related Art
[0005] A screen used in a projection-type display system includes a
microlens array sheet for spatially distributing emitted light
collimated through an optical system so that the light can have a
desired viewing angle, a black matrix layer for improving contrast
by absorbing external light and minimizing the reflection of
external light, and a light diffusion layer for diffusing the
emitted light and eliminating speckles. In particular, a black
matrix that is currently used to improve contrast is manufactured
using methods, such as a Cr/CrOx metallization method, a resin
black matrix method, a black matrix transfer method, etc.
[0006] The black matrix formation method using Cr/CrOx, which is
mainly employed in a Liquid Crystal Display (LCD), uses Cr having
an optical density of more than 3.5, so that it has characteristics
of excellent light blocking performance and chemical resistance.
However, the black matrix formation method is disadvantageous in
that the process thereof is complicated and a facility cost is
high, thus increasing the manufacturing cost because Cr/CrOx layers
having a thickness of 0.1.about.0.2 .mu.m must be sequentially laid
one on top of another and then be etched. Furthermore, since Cr has
a high reflective index, an additional process for achieving a low
reflective characteristic is necessary.
[0007] The resin black matrix method, using resin including a black
pigment, is advantageous in that it is simple because it forms a
black matrix using photolithography after applying the resin.
However, it is disadvantageous in that it is difficult to perform
photolithography because a large amount of black pigment is
required to attain high optical density and because exposure light,
such as ultraviolet light for photolithography, cannot generally
penetrate a high-density material in the depth direction thereof.
In order to achieve desired optical density, the amount of a black
pigment must be increased and the amount of resin must be
decreased, so that a patterned shape formed through a developing
process becomes rough due to the relatively small proportion of the
resin, thus causing degradation in the brightness and viewing angle
of an optical sheet having the black matrix that is formed by the
above-described method.
[0008] The black matrix formation method using a pattern transfer
technique includes a method using a light-sensitive adhesion layer
and a method using a photothermal conversion layer.
[0009] The method using a light-sensitive adhesion layer utilizes
the characteristic of a material in which portions onto which light
is radiated lose adhesiveness. This method is a method of
transferring a black matrix after radiating light onto a microlens
sheet having a light-sensitive adhesion layer. This method is
disadvantageous in that the boundary surfaces of light apertures,
which are formed by the transfer of the black matrix, are rough, so
that some light passing through the light apertures is lost.
[0010] Meanwhile, the method using a photothermal conversion layer
is a method of transferring a black matrix from a donor substrate
having a substrate, a photothermal conversion layer and a transfer
layer to an acceptor substrate on which the black matrix is to be
formed. This method is disadvantageous in that the donor substrate
is relatively complicated, so that the manufacturing cost thereof
increases.
SUMMARY OF THE INVENTION
[0011] Accordingly, the present invention has been made keeping in
mind the above problems occurring in the prior art, and an object
of the present invention is to provide a black matrix and a method
of forming the black matrix, which can improve the contrast of a
microlens array sheet.
[0012] Another object of the present invention is to provide a
black matrix and a method of forming the black matrix, which do not
affect the brightness and viewing angle of a microlens array
sheet.
[0013] In order to accomplish the above-described objects, a method
of manufacturing a microlens array sheet having a black matrix
layer in accordance with the present invention includes a) the step
of forming the regions of light apertures, through which condensed
light passes, in a negative-type light-sensitive resin layer by
radiating and condensing parallel light after sequentially laying a
microlens array layer, a transparent support substrate or film
layer and the negative-type light-sensitive resin layer one on top
of another; and b) eliminating portions other than the regions of
the light apertures formed in the light-sensitive resin layer, and
forming a black matrix layer in regions where the portions have
been eliminated.
[0014] Preferably, the present invention further includes the step
of eliminating the regions of the light apertures which are formed
in the light-sensitive resin layer and through which condensed
light passes.
[0015] Preferably, the present invention further includes a light
diffusion layer on the bottom surface of the black matrix
layer.
[0016] In the present invention, the regions of the light apertures
that are formed in the light-sensitive resin layer and through
which condensed light passes, are formed such that the area of each
region through which the condensed light enters is smaller than the
area of the region through which the condensed light is
emitted.
[0017] Preferably, in the present invention, the light-sensitive
resin layer has a light transmittance of more than 90%.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The above and other objects, features and advantages of the
present invention will be more clearly understood from the
following detailed description taken in conjunction with the
accompanying drawings, in which:
[0019] FIG. 1 is a sectional view of a conventional display
screen;
[0020] FIG. 2 is an exploded perspective view illustrating a
microlens array sheet having a black matrix layer according to an
embodiment of the present invention;
[0021] FIGS. 3A to 3D are views illustrating a process of forming a
black matrix layer in accordance with an embodiment of the present
invention;
[0022] FIGS. 4A to 4C are views illustrating a process of forming a
black matrix layer in accordance with another embodiment of the
present invention; and
[0023] FIG. 5 is a sectional view illustrating a projection display
screen having a light diffusion layer according to an embodiment of
the present invention
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0024] With reference to the accompanying drawings, the present
invention is described in detail below. In the following
description, specific items, such as specific elements, will be
described. Those are provided only to help easily understand the
present invention and, accordingly, it is apparent to those skilled
in the art that various modifications, additions and substitutions
are possible without departing from the scope and spirit of the
invention as disclosed in the accompanying claims.
[0025] FIG. 2 is a perspective view illustrating a microlens array
sheet having a black matrix layer according to an embodiment of the
present invention.
[0026] In the above embodiment, the microlens array sheet includes
a microlens array layer 31, a black matrix layer 32 and a light
diffusion layer 37.
[0027] This embodiment employs a circular convex lens as a
microlens, and schematically illustrates the sequential position of
the black matrix layer in the laying of the elements.
[0028] Referring to FIG. 2, in the microlens array sheet, the
microlens lens layer 31, the black matrix layer 32 having light
apertures formed in alignment with individual microlenses, and the
light diffusion layer 37 are sequentially laid one on top of
another, thus forming a projection screen.
[0029] FIGS. 3A to 3D illustrate a process of forming a black
matrix in a microlens array sheet according to an embodiment of the
present invention.
[0030] In this embodiment, the microlens array sheet includes a
microlens array layer 31, a transparent support substrate or film
layer 32, and a black matrix layer 36.
[0031] The embodiment schematically illustrates a process of
forming the black matrix layer 36 in which light apertures 35 are
empty.
[0032] FIG. 3A illustrates a process of forming the light apertures
35 in the light-sensitive resin layer 33. In this process, when
parallel light 34 is radiated after the microlens array layer 31,
the transparent support substrate or film layer 32 and the
negative-type light-sensitive resin layer 33 are sequentially laid
one on top of another, the parallel light 34 is condensed by the
microlens array layer 31, and light aperture regions 35, rough
which the condensed light passes, are defined in the negative
light-sensitive resin layer 33 while being self-aligned.
[0033] FIG. 3B illustrates a process of eliminating portions other
than light apertures 35 that are formed in the light-sensitive
resin layer 33. In this process, portions other than portions
exposed to light are eliminated using a developing process.
[0034] FIGS. 3C and 3D illustrate a process of forming the black
matrix layer 36 and eliminating the light-sensitive resin layer 33
that forms the light aperture 35. In this process, portions other
than portions exposed to light are eliminated using the developing
process, and the area where the portions are eliminated is filled
with black material having considerably low light transmissivity
and considerably low reflectance. The black matrix layer 36 is
formed by selectively eliminating the light apertures 35 and the
self-aligned and patterned light-sensitive resin layer.
[0035] As described above, optical loss is minimized by defining
the pattern of the light apertures 35 in a self-assignment fashion
and forming the black matrix layer 36 in the regions other than the
light apertures 35, and the improvement of brightness can be
achieved by increasing the transmissivity of the microlens array
sheet. Furthermore, the shape of the light apertures 35 is
trapezoidal, so that there is an effect of preventing the loss of a
viewing angle cased by the black matrix.
[0036] FIGS. 4A to 4C illustrate a process of forming another black
matrix layer in a microlens array sheet according to an embodiment
of the present invention.
[0037] In this embodiment, the microlens array sheet includes a
microlens array layer 31, a transparent support substrate or film
layer 32, a black matrix layer 36, and a light-sensitive resin
layer 33 that is self-aligned with individual microlenses and
exposed to light.
[0038] The embodiment schematically illustrates a process of
forming the black matrix layer 36 in which the light apertures 35
are filled.
[0039] FIG. 4A illustrates a process of defining light apertures 35
in the light-sensitive resin layer 33. In this process, when
parallel light 34 is radiated after the microlens array layer 31,
the transparent support substrate or film layer 32 and the
negative-type light-sensitive resin layer 33 have been sequentially
laid one on top of another, the parallel light 34 is self-aligned
by the microlens array layer 31 and defines the light apertures 35
in the negative-type light-sensitive resin layer 33 in condensed
array form.
[0040] FIGS. 4B and 4C illustrate a process of eliminating portions
other than the light apertures 35 defined in the light-sensitive
resin layer 33 and forming the black matrix layer 36. In this
process, portions other than portions exposed to light in a
developing process are eliminated and the eliminated portions are
filled with black material having considerably low light
transmissivity and considerably low light reflectance, thus forming
the black matrix layer 36. In order to improve the transmissivity
of the microlens array sheet, it is preferred that the negative
light-sensitive resin layer 33 have a light transmissivity of more
than 90%. That is, in the process of forming the black matrix layer
in accordance with the present invention, which is shown in FIG.
3D, the black matrix formation may be completed without eliminating
the negative light-sensitive film.
[0041] FIG. 5 is a sectional view illustrating a projection screen
having a light diffusion layer, in accordance with an embodiment of
the present invention.
[0042] In this embodiment, the projection screen includes a
microlens array layer 31, a transparent support substrate or film
layer 32, a black matrix layer 36, light apertures 35, and a light
diffusion layer 37.
[0043] The embodiment schematically illustrates a projection screen
in which the light diffusion layer 37 is included in the microlens
array sheet.
[0044] Referring to FIG. 5, speckles can be prevented and a viewing
angle can be adjusted by adding the light diffusion layer 37 to the
bottom surface of the microlens array sheet having the black matrix
layer 36 formed by the process of FIGS. 3A to 3D. In order to
obtain desired brightness and viewing angle characteristics, the
light apertures 35 may be replaced with material having a specific
reflective index. In particular, a lenticular or holographic
surface-type is light diffusion layer 37 has a feature in which
viewing angle characteristics are considerably degraded when an
adhesion layer comes into contact with the lenticular or
holographic surface that has surface projections and depressions in
charge of diffusion. Accordingly, when the light apertures 35 are
emptied and the light diffusion layer 37 is attached onto the
bottom surface of the black matrix layer 36, surfaces in contact
with the lenticular or holographic surface of the light diffusion
layer 37 do not exist in the regions of the light apertures 35, so
that desired viewing angle characteristics provided by the
lenticular or holographic surface-type diffusion layer can be
achieved.
[0045] As described above, the present invention provides the
microlens array sheet applicable to projection screens and the
manufacturing method thereof, which can prevent the loss of light
that occurs when light emitted from the microlens array sheet is
blocked by the black matrix layer, thus providing high brightness
and a wider viewing angle to users.
[0046] In particular, the present invention method of filling
necessary regions with a black pigment having a considerably low
transmittance and a considerably low reflective index after
photolithography is simpler than the existing complicated process,
and is appropriate for the mass production of projection screens to
which the optical sheet is applied.
[0047] Although the preferred embodiments of the present invention
have been disclosed for illustrative purposes, those skilled in the
art will appreciate that various modifications, additions and
substitutions are possible, without departing from the scope and
spirit of the invention as disclosed in the accompanying
claims.
* * * * *